An autonomous vehicle is a vehicle capable of fulfilling the human transportation capabilities of a traditional vehicle but without human input. Generally these vehicles tend to rely on radar, computer vision, Lidar, and sensors of different kind. Vehicles having autonomous driving systems, especially vehicles such as autonomous vehicles, run the risk of accidentally hitting objects not intended to. Some autonomous vehicles have a 360 degree sensor field of view to detect if an object is within a defined risk zone and thus risking to get hit by the autonomous vehicle. The high safety requirements impart equally high demands on the vehicle systems. For autonomous vehicles, the safety requirements are very high as the human is completely removed from the decision- and interaction process of driving the vehicle.
A problem with existing autonomous vehicles and especially some autonomous driving systems are however that they tend to be insensitive for objects which are not moving and less sensitive during initial motion of the vehicle. A particularly difficult scenario is when the vehicle is parked and the autonomous driving systems are shut down. The vehicle is vulnerable during such period as the vehicle cannot keep track of its surroundings and objects may be positioned around or underneath the vehicle which the vehicle cannot detect with the autonomous driving systems when the vehicle starts. If the operator of the autonomous vehicle at that time requests the vehicle to move, the vehicle or the objects may be damaged, as the ordinary autonomous driving systems may not detect the object, or may not yet have enough data to draw the correct conclusions about the micro traffic situation, i.e., the imminent surroundings of the vehicle.
The published U.S. Pat. No. 8,473,173 B1 discloses a vehicle having an automatic braking system. The automatic braking system can be provided with sensors to detect a trigger event. If a trigger event is detected the automatic braking system is actuated. The U.S. Pat. No. 5,598,164 discloses a system for warning a driver. The system detects if an obstacle is present at the front, rear or at the sides of the vehicle. If an obstacle is detected, the vehicle is prevented from moving forward or backwards. The system e.g., uses heat sensors, motion sensors or radars to detect the objects. Both the mentioned solutions above rely heavily on the use of proximity sensors to detect the objects.
There is however a need to provide improved methods and vehicles for detecting obstructing objects which may have been positioned to obstruct the vehicle when the normal autonomous driving systems are not in use, or to provide a complementary detection function to a vehicle which effectively limits the risk for accidents with objects in the near surrounding when the vehicle starts from a standstill position.